I'm sure the guy who sold me my PT111 G2 9mm told me, but I'm not clear on how the trigger works. Sometimes there is a firm pull and sometimes you pull almost all the way with no resistance before the gun fires. Is this normal, or is something wrong with my gun? I also get at least one, sometimes 2 or 3 misfires per clip of 10. What's up with that?

I have one and it has a sa/da trigger. It even says so in the manual that comes with it which nobody reads. A quick test to be certain is to take the mag out, rack the slide, dry fire the weapon (which you will notice its a single action pull), then dry fire it again. On the second dry fire is where you will see the double action trigger pull. Also there are a couple different models of the g2. Mine (the compact model) does not have a decocking lever to put it in double action mode for the first trigger pull but the full size version does.

IMO, Taurus mis-labeled the 24/7 Pro DS, Millennium Pro and Millennium G2 as SA/DA. As Pasquanel said, these pistols in fact are in SA always unless when there is a misfired round, the trigger would switch to DA for the second strike and then the trigger would return to SA once the misfired round is cleared. On the 24/7 Pro DS/Pro C DS pistols, you can decock the gun to make the 1st shot DA thanks to the decocker safety.

On the other hand, the 24/7 G2 pistols are true DA/SA, 1st shot DA then the rest will be in SA unless there is a misfired round, the trigger would switch to DA for the 2nd strike and after the misfired round is cleared, the trigger would switch back to SA.

Edit: The 24/7 Pro/Pro C DS and 24/7 G2 guns have the cocking indicator to help us easily tell when the trigger is in SA and when it's in DA. On the Millennium guns, because they don't have the cocking indicator, we have to feel the long trigger pull of the DA trigger.